1. Field of the Invention
The present invention relates to fluid heater tubing coils and more particularly pertains to a new spiral fluid heater coil system for facilitating drainage of fluid from the heater and increasing the efficiency of transferring heat to a fluid.
2. Description of the Prior Art
Devices for pressurizing and heating fluid are known in the art. One type of fluid heating device uses combustion of a fuel in a combustion chamber to heat fluid moving through a helical coil of tubing located in the combustion chamber. Typically, a burner is located at one end of the combustion chamber, and one or more coils of the tubing are typically located in the chamber toward the other end of the chamber. The burner directs a flame toward the coils of tubing such that the hot combustion gases move around the tubing.
The coiled tubing for moving fluid through the fluid heating device periodically needs to be drained, such as, for example, prior to maintenance of the fluid heating device, or prior to exposure to freezing temperatures, or prior to extended periods of non-use of the device to minimize corrosion of the fluid heating device. However, the conventional and predominant fluid heater design positions several helical coils of tubing in an upper portion of the combustion chamber to increase heat transfer to the fluid. The multiple helical coils are typically positioned in a coaxial arrangement with inner helical coils positioned or nested inside outer helical coils to form a relatively dense package of coils. The coils are connected together in a series, so that the fluid flows in an upward direction in one helical coil, in a downward direction in another helical coil, upward in still another helical coil, and so forth. The up and down undulations in the fluid path make it extremely difficult, if not impossible, to completely drain the fluid from the series of helical coils when necessary.
A system of helical coils is also relatively inefficient for producing heat transfer, because there are vertical air gaps between the coils through which the hot gases can pass without contacting the coils and many portions of the coils receive very limited exposure to the heated gases because of the dense vertical packing of the coils. Thus, helical coil systems are relatively inefficient and therefore typically require relatively long lengths of tubing to achieve a desirable level of heat transfer.
Sporadic attempts have been made to utilize spiral coils of tubing in fluid heater devices. However, manufacturing difficulties in fabricating such spiral coils have prevented the common use of spiral coils in fluid heaters. A single coil of tubing in a fluid heater is generally insufficient to achieve a desirable level of heat transfer to the fluid from the heated gases of the combustion chamber. Thus, more than one spiral coil must be used, but manufacturing difficulties have made such an arrangement very difficult to manufacture and utilize more than one spiral coil in a practical manner. The conventional manner of forming the spiral coils is to form each of the spiral coils separately and then join the spiral coils together in a series. However, linking the tubing of each of the spiral coils is difficult, since a weld is necessary at the end of the tubing located at the center of each of the coils for linking to an adjacent coil, especially if more than two coils are used. Further, the density (e.g., radial proximity) of each spiral of the spiral coil and the axial proximity of adjoining spiral coils has been limited by conventional fabrication processes.
The spiral fluid heater coil system according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus which facilitates drainage of fluid from the heater, provides a smaller, more compact, dense coil arrangement, and increases the efficiency of transferring heat to a fluid compared to conventional concentric helical coil configurations.
In view of the foregoing disadvantages inherent in the known types of fluid heater tubing coils now present in the prior art, the present invention provides a new spiral fluid heater coil system construction wherein the same can be utilized for facilitating drainage of fluid from the heater and increasing the efficiency of transferring heat to a fluid.
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new spiral fluid heater coil system apparatus and method which has many of the advantages of the fluid heater tubing coils mentioned heretofore and many novel features that result in a new spiral fluid heater coil system which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art fluid heater tubing coils, either alone or in any combination thereof.
To attain this, the present invention generally comprises a heater assembly including a combustion chamber having a chamber perimeter wall defining a chamber interior. The chamber perimeter wall has an upper end and a lower end, with the upper end of the chamber perimeter wall defining an opening into the chamber interior. The heater assembly includes a burner apparatus for burning fuel and expelling heat into the chamber interior of the combustion chamber, with the burner apparatus being positioned adjacent the lower end of the chamber perimeter wall for directing heat upwardly in the chamber interior toward the upper end of the chamber perimeter wall. The heating assembly includes a heating conduit for moving fluid through the heater housing to heat the fluid. The heating conduit has a heating portion positioned adjacent to an opening in the upper end of the chamber perimeter wall of the combustion chamber for permitting heat from the chamber interior to pass through the heating portion of the heating conduit. The heating portion includes at least one tier, and the tier comprises a spiral coil having a plurality of spirals lying substantially in a common plane. Preferably, the heating conduit includes an upper tier oriented above a lower tier, and an innermost spiral of the lower tier is connected to an innermost spiral of the upper tier such that fluid is moved from an outermost spiral of the lower tier to the innermost spiral of the lower tier to the innermost spiral of the upper tier to an outermost spiral of the upper tier, for each pair of spiraled heating sections.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
Various objects of the invention, along with the various features of novelty which characterize the invention, are described below in the detailed description and pointed out with particularity in the claims annexed to and forming a part of this disclosure.
For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated preferred embodiments of the invention.